12161261 has 6 divisors (see below), whose sum is σ = 14146830. Its totient is φ = 10423896.

The previous prime is 12161251. The next prime is 12161287. The reversal of 12161261 is 16216121.

It can be written as a sum of positive squares in only one way, i.e., 8236900 + 3924361 = 2870^2 + 1981^2 .

It is not a de Polignac number, because 12161261 - 2¹⁸ = 11899117 is a prime.

It is a super-2 number, since 2×12161261² = 295792538220242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12161251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 124046 + ... + 124143.

It is an arithmetic number, because the mean of its divisors is an integer number (2357805).

Almost surely, 2^12161261 is an apocalyptic number.

It is an amenable number.

12161261 is a deficient number, since it is larger than the sum of its proper divisors (1985569).

12161261 is an equidigital number, since it uses as much as digits as its factorization.

12161261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248203 (or 248196 counting only the distinct ones).

The product of its digits is 144, while the sum is 20.

The square root of 12161261 is about 3487.2999584206. The cubic root of 12161261 is about 229.9638317418.

Adding to 12161261 its reverse (16216121), we get a palindrome (28377382).

The spelling of 12161261 in words is "twelve million, one hundred sixty-one thousand, two hundred sixty-one".